Three‐dimensional computed tomographic angiography (3D‐CTA) is widely used to evaluate the inner diameters of vessels and the anatomical vascular structure prior to endoscopic aortic surgery or transcatheter valve implantation. Virtual monoenergetic imaging (VMI) is a new application in dual‐energy CT (DECT). We evaluated the potential for contrast dose reduction in preoperative aortic CTA using VMI. To evaluate performance in terms of image quality and vessel shape, we quantified the contrast‐to‐noise ratio (CNR) and the vessel diameter using a cylinder phantom we developed, and used volume rendering to assess visual quality. All VMI had improved CNR values compared with conventional 120 kVp images at an iodine content of 15 mgI/mL. In each image, a virtual mono‐energy of 40 keV yielded the highest CNR value, and an iodine content of 9 mgI/mL was comparable to that of conventional images with an iodine content of 15 mgI/mL. The circularity indices (CI) of the vascular model at 15, 12, and 9 mgI/mL were similar to those of the reference condition using conventional voltages; however, CI was degraded at iodine contents of 6 and 3 mgI/mL with VMI.

中文翻译：

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使用虚拟单能成像对主动脉CTA降低造影剂剂量。

三维计算机断层血管造影（3D-CTA）被广泛用于评估内窥镜主动脉手术或经导管瓣膜植入术之前血管的内径和解剖血管结构。虚拟单能成像（VMI）是双能CT（DECT）的新应用。我们评估了使用VMI降低术前主动脉CTA造影剂剂量的潜力。为了评估图像质量和血管形状方面的性能，我们使用开发的圆柱体模量化了对比噪声比（CNR）和血管直径，并使用体积渲染来评估视觉质量。与15 mgI / mL碘含量的传统120 kVp图像相比，所有VMI的CNR值均得到改善。在每张图像中，虚拟的40 keV单能产生了最高的CNR值，碘含量为9 mgI / mL，与碘含量为15 mgI / mL的常规图像相当。血管模型在15、12和9 mgI / mL时的圆度指数（CI）与使用常规电压的参考条件相似。但是，用VMI在CI的碘含量为6和3 mgI / mL时，CI被降解。